Electric circuit breaker



Aug. 18, 1936. w. UEBERMUTH 2,051,659

ELECTRIC CIRCUIT BREAKER Filed Aug. 19, 1935 iii! INSULATION InvenLorwer-ner" Uebe-muLh, y 9 I His ttor'neg projects beyond the valve proper at o' into the cylinder 6, the other end of the valve stem being e guided in the casing 3 and provided with means at H for adjusting the length of the valve stem exteriorly of the casing.

A piston |2 is mounted within the cylinder 6 and is operatively connected'through 'pisten red !3, lever M, and insulating link is to the movable contact 2. operation of the lever M is efi'ected by the shaft IS connected to suitable actuating means (not shown). With the switch in the closed circuit position shown, operation of the lever ll in counter-clockwise direction causes downward or opening movement of the contact 2` and an upward sti-oke of piston :2 compressing the gas within the cylinder 6. However, no blast is directed between the contacts until the piston !2 abuts and moves the valve stern extension lo" upwardly, thereby opening the valve 1 and causing at that instant a blast of gas un der pressure through the passage 5 and across the arc at the contact I. Accordingly, since the movable contact and pisten are operatively connected the gas blast may be considered as directed either in accordance with the position of the movable contact or the position of the piston.

Through the use of the special control member, as the valve 1, it is likewise possible to make the intensity of the gas blast particularly favorable and suitable during the period of arc interruption, for example in such a manner that at the beginning the blast can be kept somewhat weaker and then strengthened, or vice versa, or be maintained constant during extinguishing of the arc. In contrast with this, in prior types of pressure gas switches with automatic compression a relatively strong blast is created at the beginning of the operation and, as the amount of the pressure gas available is small, the blast decreases considerably towards the end of the interrupting operation. It is, therefore, not only possible in accordance with my invention to limit the gas leakage losses to an extent approaching the ideal condition, but also to obtan the ultimate maximum of interrupting capacity with a given work of compressio i As" regards the heating of the contacts and insulating parts of the switch. it is -likewise advantageous to direct the gas blast through the arc only at the contact position most favorable to are extinction, since the voltage and the heat generated by the arc can be kept small at the beginning of the operation.

The time at which the gas blast is applied with respect to separation of the contacts can be determined by adjusting the length of the valve stern at ll so that 'the stem extends a greater or less extent into the cylinder 6. The stern I 0, of course, may be adjustably secured to the valve 'I 'such asby screw threaded engagement so that rotaton of stem n causes longitudinal movement of the stern with respect to the valve.

In another form the valve control may be in accord-ance with the pressure developed in the cylinder 6, for example the valve 'I being opened in response to a predetermined pressure developed by the piston !2. It will be apparent that the valve spring 8 may be suitably adjusted to provide for opening under varying conditions.

It should be understood that my invention is not limited to specific details of Construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric circuit breaker 'of the gas blast type comprising relatively movable Contacts, a. pisten for compressing a quantity of gas, means operatively connecting said pisten and Contacts,

a valve for controlling release of said gas to a.

point of contact separation for extinguishing arcng, means for causing positiveopening of said valve in accordance with a predetermined position of said piston, and means for adjusting said last-named means for varying "said predetermined position.

2. An electric circuit breaker of the gas blast type comprising relatively movable contacts, a pisten forcompressing a quantity of gas "operatively connected to one of said contactsf means forming a passage between said pisten and the point of contact separation, a valve biased normally to close said' passage, means operatively connected to said valve causing positive opening thereof in accordance with a predetermined position of said last-named contact, and means for varying the opening of said valve with respect to said contact and piston.

WERNER UEBERMUTH. 

